The present invention relates to a cleaning device for a rotor spinning unit with a cleaning head and an extensible device for the extension and retraction of at least the cleaning head.
In a known rotor spinning machine a traveling service unit contains a cleaning device for the cleaning of a spinning rotor (DE 24 57 034 A1). The cleaning device has a telescope-like extensible compressed-air pipe whose forward end can be retracted in part once the service unit has positioned itself in front of the spinning rotor. At the forward end of the compressed-air pipe a nozzle to blow out the compressed air and a cleaning brush are provided for the cleaning of the inside of the rotor plate. During the cleaning process, compressed air is blown out of the nozzle and the telescopic pipe is rotated by a motorized drive so that the cleaning brush rotates inside the rotor plate.
It is an object of the present invention to provide a cleaning device for a rotor spinning unit that would make it possible to achieve a constantly high cleaning effect and adaptation to a modified rotor spinning unit while simplifying maintenance of the cleaning device. Additional objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
According to an embodiment of the invention, a cleaning device with a cleaning head and an extensible device for extension and retraction of at least the cleaning head is provided for a rotor spinning unit. The extensible device can be designed as an extensible telescoping device, a swiveling device, a combination of swiveling and telescoping device or similar device. The cleaning head is positioned by means of the extensible device e.g. in the rotor plate of a spinning rotor or directly adjoining a yarn draw-off nozzle. The cleaning device is preferably placed in a service unit traveling e.g. along a plurality of spinning stations of a rotor spinning machine. By displacing and aligning the service unit, it is positioned across from the rotor spinning unit in such manner that the cleaning head can be positioned by the extensible device in or at the element of the rotor spinning unit to be cleaned. The cleaning head may be equipped with at least one compressed-air nozzle, at least one scraper, at least one cleaning bristle or a combination of these elements. Due to the fact that the cleaning head is replaceable and connected to the extensible device, it can simply be replaced when worn or dirty. This is necessary, for example, when a scraper, a bristle or a nozzle of the cleaning head is soiled or clogged up. Or else a replacement can be made when e.g. an element of the rotor spinning unit is replaced in order to provide a cleaning head that is adapted to the inside and/or outside form of the replaced element. Optimal cleaning of the replaced element of the rotor spinning unit can then be achieved with the adapted cleaning head. An example of a replaceable element is a spinning rotor that has a different rotor pot geometry after the replacement.
If the cleaning head is used to clean a spinning rotor, preferably at least one first cleaning element is assigned to the rotor channel and at least one second cleaning element to the rotor side. By assigning the cleaning elements, these can be adapted especially to the shape of the rotor pot in order to clean the channel and e.g. the sidewalls or the bottom of the rotor pot by means of specially designed cleaning elements. While mostly fibers must be removed from the rotor channel after a yarn breakage for example, rather resistant dirt must be removed from the pot bottom or from the sloped sidewall. In one embodiment for example, it is advantageous to clean the rotor channel by means of one or several bristles, while the sidewalls are scraped by means of a scraper.
In a variant of the invention, a first and a second cleaning head are installed on the extensible device, whereby the first one is provided for the cleaning of a spinning rotor and the second one for the cleaning of a yarn draw-off nozzle. They are preferably at such distance from each other or can be positioned by the extensible device at such distance from each other that in their end positions the first cleaning head is positioned in the spinning rotor while the second cleaning head is positioned at the yarn draw-off nozzle. Each cleaning head can be driven by its own drive unit or by a common drive unit.
In a first embodiment, the cleaning head, of which at least one is provided, is held in a seat installed on the extensible device. In another embodiment, the cleaning head, of which at least one is provided, is mounted on a drive unit to rotate the cleaning head and is replaceable. If several cleaning heads are used, a holder can be provided on fixed seats and/or drive units. In case of a fixed seat, the element to be cleaned, e.g. the spinning rotor, can be put in motion by a separate drive that may be mounted e.g. on the extensible device or by a drive already used for the element to be cleaned.
If the cleaning head is attached by means of a catch or snap-in connection that can be opened, or by means of a bayonet connection to the seat or to the driving unit, the cleaning head can be replaced quickly, e.g. without any tool.
In an advantageous embodiment of the cleaning head for the cleaning of a yarn draw-off nozzle, the rotational axis of the cleaning head is not aligned coaxially with the symmetry axis of the yarn draw-off nozzle. The cleaning head rotating at an angle seizes deposits on the yarn draw-off nozzle and transports them to its edge. As soon as the impurities have been transported over the edge of the yarn draw-off nozzle, they are thrown off at that location by the cleaning head. Thereby the dirt adhering to the cleaning elements is prevented from being transported in a circular motion to the yarn draw-off nozzle without finally being removed from it.
In another embodiment of the cleaning head, the latter is supplied with compressed air and the compressed air is blown from the nozzle in the direction of the element to be cleaned. The bristles and/or scraper of the cleaning head are advantageously placed at a distance from the nozzle. As a result, the nozzle can blow directly on the element of the rotor spinning unit to be cleaned. In addition, the dirt loosened by the compressed air from the element to be cleaned is carried away from the soiled area. Here, the bristles and/or scraper advantageously provide a free passage for the compressed air at the outer circumference of the cleaning head so that the loosened impurities are blown away from the cleaning head and the element to be cleaned between the bristles and/or the scrapers.
In another embodiment, the seat and/or the drive unit are provided with a compressed-air supplying device with a locking device for the cleaning head. When the cleaning head is used, an actuator of the cleaning head actuates the locking device of the seat or the drive unit so that the locking device opens the compressed-air passage to the cleaning head. Here, the compressed-air passage to the cleaning head is closed by the locking device when the cleaning head is removed from the seat or the drive unit or when the inserted cleaning head does not have an actuator, e.g. when the cleaning head does not need compressed air.
In an advantageous embodiment, the extensible unit of the cleaning device is a combination of a linear-movement device executing a linear back and forth movement in one direction, and of an extensible arm that is moved by a telescoping guide and is capable of pivoting. The extensible unit can then execute a linear movement simultaneously with a swiveling movement. In this way, a complex and precise movement of the extensible arm becomes possible with little mechanical expenditure. If the cleaning device is installed e.g. on a service unit, a cleaning head for the cleaning of the spinning rotor or the extensible unit in rest position need not be positioned directly in a position across from the rotor. Only for cleaning is the cleaning head extended from a border zone of the service unit towards the spinning rotor. Thereby it is possible to place e.g. a piecing unit for the piecing of the yarn on the service device directly across from the rotor without crowding the cleaning device in such a configuration.
In another embodiment, the cleaning head has at least one cleaning element that comes into contact with the element to be cleaned at least intermittently during the rotation and thereby cleans it. At least one compressed-air nozzle is installed on the rotating cleaning head to blow air into the contact zone between the cleaning element and the element to be cleaned, at least when contact is made between at least one cleaning element and the element to be cleaned. In that case, the compressed air reaches the contact zone situated in the sense of movement of the cleaning element. Thereby, a removal of the dirt deposit by blowing in the area most affected by dirt deposits within range of one or several cleaning elements is ensured.
In an advantageous embodiment, the cleaning element or cleaning elements are not evenly distributed around the outer circumference of the cleaning head, but the cleaning elements are arranged with distances or gaps between them on the outer circumference so that the compressed-air nozzle can blow into the gaps. In another embodiment, at least one compressed-air nozzle can be positioned in such a manner relative to the rotating cleaning head so that the stream of compressed air coming from the compressed-air nozzle is directed into the path of the (at least one) cleaning element.
If the cleaning head is mounted so as to be capable of movement relative to the compressed-air nozzle, or if the compressed-air nozzle is mounted so as to be capable of movement relative to the cleaning head, a movement of the two elements relative to each other makes it possible to blow over different areas of the cleaning head. In an especially advantageous embodiment, the compressed-air nozzle is used to clean the cleaning head as well as the element to be cleaned. In that case, the compressed air is blown on the element to be cleaned when the nozzle or the cleaning head is in a first position, so that it is freed of deposited dirt. In a second position of the compressed-air nozzle or of the cleaning head, the stream of compressed air is directed on the cleaning head, so that the latter is blow-cleaned preferably while it rotates.
For the cleaning of a yarn draw-off nozzle, the compressed-air nozzle is aligned preferably coaxially with the yarn draw-off nozzle, so that the stream of compressed air that is blown through the yarn draw-off nozzle continues into the yarn draw-off direction that follows.
An example of an embodiment of the invention is explained through figures.